. >> thank you, leyla gulen. a massive international tribute for nelson mandela is underway this morning in south africa. a joyful crowd dancing in the stadium, president obama along with international leaders past and present in the stands. we have been following the celebration through the night from washington, dc. >> good morning. a cold and rainy day in johannesburg but the streets are electric. at the stadium, dignitaries from around the world have gathered with thousands to remember a man who changed the world. >> they came in drenching rain. tens of thousands singing, dancing, and screaming nelson mandela's name. >> nelson mandela, viva. >> the memorial service at the stadium in johannesburg, with 94 ,000 seat soccer facility is where nelson mandela made the final appearance in 2010 and together a grateful world gathered to say good by. >> remember him for the righteousness which he has